Unichem has a large warehouse facilities on the outskirts of Dublin. Vitax managing director Paul Gooding said: "Unichem’s appointment follows a complete review of our distribution network in Ireland.
"The Irish market is changing and Unichem’s knowledge and contacts both in retail and commercial markets will be essential to our future plans. Changing distributors was not a decision taken lightly but we feel Unichem’s customer profile and ambition closely matched our own going forward."
The appointment follows a period of growth for Vitax with a specific focus on developing its organic and biodegradables product ranges.
Earlier this year the company purchased Organico Limited, known for the manufacture of the popular 6X chicken fibrous fertiliser brand.
Unichem will replace McLoughlin RS who has worked with Vitax for five years.